A controversial herbal drug for dengue has been claimed by its inventor to have passed a phase III clinical trial in Indonesia, and the claims about 'cure for dengue' have been making rounds on the Internet, but some scientists have questioned any such claims as unsubstantiated.

The alleged drug was invented by Max Reynolds, a retired Australian scientist from Griffith University, using the concentrate of Melaleuca alternifolia, also known as tea tree, a shrub native to Australia.

The drug reportedly has antiviral characteristics and is said to cure all four strains of dengue.

The claims have reached Kenya this month, with The Star reporting that "Local medics have welcomed development of a drug that can completely cure dengue fever" (16 December).

But doctors and scientists in Australia doubt the drug's reported ability to cure dengue.

Cameron Webb, scientist and clinical lecturer at Marie Bashir Institute of Infectious Diseases and Biosecurity, University of Sydney, says results of the trials have not been published yet and Reynolds' report on his new drug is not in any peer-reviewed journals and, therefore, could not be validated.

"It is impossible to make a judgement on the effectiveness of any drug, or the manner in which clinical trials were undertaken, without seeing the work — ideally through publication in an internationally recognised peer-reviewed publication," Webb tells SciDev.Net.

Reynolds says he conducted the first stage of his clinical trial on animals in University of Gajah Mada, Yogyakarta, in 2006. The reported success of the trial led to a second stage, where Reynolds says he administered the drug to a group of healthy humans at the University of Indonesia. He then approached the research division of Indonesia's Ministry of Health to get their permission in conducting the third stage of the trial, where he applied the drug to 504 people with dengue fever in hospitals and government's clinic in Indonesia.

Siswanto, head of the Centre for Applied Health Technology and Epidemiology Clinic in Indonesia's Ministry of Health, says his office is supportive of Reynolds' invention because Indonesia has a large prevalence of dengue — about 10,000 cases each year — so it is interested in research on a cure for the disease.

Reynolds' company Neumedix, which funded all the clinical trials, has applied for an approval from Indonesia's National Agency for Food and Drugs Control (BPOM) to manufacture the drug. If the company gets a licence, it plans to release the drug in tablet form to the local market sometime in 2014 at US$50 per bottle.

Webb criticized the definition of "success" in the clinical trials that Reynolds and the Indonesian scientists' claim.

"What was the measure of success in the treatment of human cases?" he asks, adding that it is not clear what claims about decrease in viral load mean in "relation to human disease unless full details of the result are made available and can be reviewed".

Steven Donohue, a physician from Queensland Public Health, told ABC Radio Australia (28 September) that he would not recommend anyone use the drug.

"All they have done is show that the well-known antiseptic properties of tea tree are able to kill dengue and other viruses in a test tube which we already knew," he said.

Tarik Jasarevic, WHO's media relations officer, says, "We haven't seen research from the clinical trials so we cannot comment on the effectiveness of the product."

Jasaveric adds: "It is not our practice to comment on new medical products before it is approved by a national regulatory agency."

Both Siswanto and Nasronudin, head of the Institute of Tropical Diseases at the University of Airlangga, say they are not aware of the criticisms against Reynolds' drug and defend their research collaboration with Reynolds.

"Our task as scientists is to do research. It is up to the public whether they want to accept the result of our research or not," Nasronudin asserts.